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Table 2 Mean of the predictive ability estimates (Est), mean of the standard error estimates SE and standard error of the estimates (SE).

From: Multiple imputation for estimating hazard ratios and predictive abilities in case-cohort surveys

   β 1 = β 2 = β 3 =0   β 1 = β 3 = log(2), β 2 = log(1.5) β1 = β2 = β3 = log(2)
  Est SE SE % H 0 rejected Est SE SE % H 0 rejected Est SE SE % H 0 rejected
Full Cohort             
C 1 0.518 0.033 0.012   0.727 0.032 0.015   0.733 0.029 0.014  
C 2 0.524 0.033 0.013   0.747 0.031 0.015   0.733 0.029 0.014  
Δ 0.006 0.010 0.009 3.7 0.020 0.007 0.007 91.6 0.049 0.010 0.010 100
NRI 0.007 0.017 0.019 4.8 0.071 0.030 0.033 52.5 0.167 0.034 0.035 99.9
IDI 2e-4 2e-4 3e-4 6.0 0.014 0.003 0.005 99.9 0.048 0.006 0.009 99.9
MI1000             
C 1 0.518 0.033 0.012   0.724 0.032 0.016   0.733 0.029 0.014  
C 2 0.526 0.033 0.013   0.745 0.031 0.016   0.783 0.027 0.014  
Δ 0.008 0.012 0.010 3.4 0.021 0.008 0.008 90.6 0.049 0.010 0.011 100
NRI 0.009 0.019 0.017 1.5 0.076 0.033 0.033 64.8 0.172 0.037 0.036 100
IDI 3e-4 3e-4 4e-4 3.5 0.014 0.004 0.005 99.0 0.045 0.008 0.010 100
MI300             
C 1 0.518 0.033 0.012   0.724 0.032 0.016   0.733 0.029 0.014  
C 2 0.528 0.033 0.012   0.745 0.031 0.017   0.783 0.027 0.015  
Δ 0.010 0.014 0.011 3.0 0.021 0.008 0.009 84.6 0.050 0.011 0.012 100
NRI 0.013 0.023 0.018 1.3 0.076 0.035 0.035 57.0 0.172 0.039 0.039 99.7
IDI 4e-4 4e-4 5e-4 1.8 0.014 0.005 0.006 87.5 0.046 0.010 0.012 100
CC1000             
C 1 0.528 0.032 0.013   0.667 0.033 0.015   0.670 0.031 0.014  
C 2 0.534 0.033 0.015   0.709 0.032 0.022   0.737 0.029 0.014  
Δ 0.006 0.010 0.010 4.7 0.043 0.011 0.017 100 0.067 0.012 0.012 100
NRI 0.017 0.031 0.033 6.7 0.147 0.039 0.043 96.7 0.261 0.041 0.043 100
IDI 0.002 0.001 0.003 15.2 0.058 0.009 0.014 100 0.114 0.011 0.017 100
CC300             
C 1 0.523 0.034 0.013   0.620 0.037 0.016   0.620 0.034 0.015  
C 2 0.529 0.034 0.015   0.647 0.036 0.016   0.668 0.032 0.015  
Δ 0.006 0.010 0.009 3.6 0.027 0.011 0.011 83.3 0.048 0.013 0.013 99.8
NRI 0.019 0.039 0.043 6.2 0.154 0.043 0.050 94.4 0.257 0.046 0.051 99.9
IDI 0.002 0.001 0.003 13.9 0.040 0.008 0.014 99.8 0.078 0.010 0.017 100
  1. Results from 1000 simulations
  2. C 1 Harrell's C index of the proportional hazard model without the phase-2 variable
  3. C 2 Harrell's C index of the proportional hazard model with the phase-2 variable
  4. Δ, Harrell's predictive value of the phase-2 variable, H 0: Δ = 0
  5. NRI, Net reclassification index by adding the phase-2 variable, H 0: NRI = 0 IDI, Integrated discrimination index by adding the phase-2 variable, H0: IDI = 0
  6. Cohort, full cohort estimates; MI300, MI1000: multiple imputation estimates with subcohort sizes set, respectively, at 300 and 1,000; CC300, CC1000, case-cohort estimates with subcohort sizes set, respectively, at 300 and 1,000